The pathobiology of human coronary atheroma: contributions of interventional cardiology

The development of coronary angiography facilitated a complete new assessment of coronary circulation in humans, opening a new age in the study and treatment of coronary artery disease. A second revolution came from furrher developments of cardiac catheterisation that made possible the performance of percutaneous therapeutic procedures in the coronary arteries. During the last: 10 years balloon angioplasry has become not only a useful therapeutic tool for clinicians, but also as a model of myocardial ischaemia and vessel wall damage for researchers. More recendy, the development of new percutaneous intracoronary devices has provided new opportunities in the study of the pathophysiology of coronary artery dis

Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes.

OBJECTIVES: The aim of this study was to investigate the clinical outcomes of patients deferred from coronary revascularization on the basis of instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) measurements in stable angina pectoris (SAP) and acute coronary syndromes (ACS). BACKGROUND: Assessment of coronary stenosis severity with pressure guidewires is recommended to determine the need for myocardial revascularization. METHODS: The safety of deferral of coronary revascularization in the pooled per-protocol population (n = 4,486) of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) and iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trials was investigated. Patients were stratified according to revascularization decision making on the basis of iFR or FFR and to clinical presentation (SAP or ACS). The primary endpoint was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year. RESULTS: Coronary revascularization was deferred in 2,130 patients. Deferral was performed in 1,117 patients (50%) in the iFR group and 1,013 patients (45%) in the FFR group (p < 0.01). At 1 year, the MACE rate in the deferred population was similar between the iFR and FFR groups (4.12% vs. 4.05%; fully adjusted hazard ratio: 1.13; 95% confidence interval: 0.72 to 1.79; p = 0.60). A clinical presentation with ACS was associated with a higher MACE rate compared with SAP in deferred patients (5.91% vs. 3.64% in ACS and SAP, respectively; fully adjusted hazard ratio: 0.61 in favor of SAP; 95% confidence interval: 0.38 to 0.99; p = 0.04). CONCLUSIONS: Overall, deferral of revascularization is equally safe with both iFR and FFR, with a low MACE rate of about 4%. Lesions were more frequently deferred when iFR was used to assess physiological significance. In deferred patients presenting with ACS, the event rate was significantly increased compared with SAP at 1 year.info:eu-repo/semantics/publishedVersio

Directional atherectomy: combining basic research and intervention

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Histologic characteristics of tissue excised during directional coronary atherectomy in stable and unstable angina pectoris

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Characterization of quantitative flow ratio and fractional flow reserve discordance using doppler flow and clinical follow-up

The physiological mechanisms of quantitative flow ratio and fractional flow reserve disagreement are not fully understood. We aimed to characterize the coronary flow and resistance profile of intermediate stenosed epicardial coronary arteries with concordant and discordant FFR and QFR. Post-hoc analysis of the DEFINE-FLOW study. Anatomical and Doppler-derived physiological parameters were compared for lesions with FFR+QFR− (n = 18) vs. FFR+QFR+ (n = 43) and for FFR−QFR+ (n = 34) vs. FFR−QFR− (n = 139). The association of QFR results with the two-year rate of target vessel failure was assessed in the proportion of vessels (n = 195) that did not undergo revascularization. Coronary flow reserve was higher [2.3 (IQR: 2.1–2.7) vs. 1.9 (IQR: 1.5–2.4)], hyperemic microvascular resistance lower [1.72 (IQR: 1.48–2.31) vs. 2.26 (IQR: 1.79–2.87)] and anatomical lesion severity less severe [% diameter stenosis 45.5 (IQR: 41.5–52.5) vs. 58.5 (IQR: 53.1–64.0)] for FFR+QFR− lesions compared with FFR+QFR+ lesions. In comparison of FFR−QFR+ vs. FFR-QFR- lesions, lesion severity was more severe [% diameter stenosis 55.2 (IQR: 51.7–61.3) vs. 43.4 (IQR: 35.0–50.6)] while coronary flow reserve [2.2 (IQR: 1.9–2.9) vs. 2.2 (IQR: 1.9–2.6)] and hyperemic microvascular resistance [2.34 (IQR: 1.85–2.81) vs. 2.57 (IQR: 2.01–3.22)] did not differ. The agreement and diagnostic performance of FFR using hyperemic stenosis resistance (> 0.80) as reference standard was higher compared with QFR and coronary flow reserve. Disagreement between FFR and QFR is partly explained by physiological and anatomical factors. Clinical Trials Registration https://www.clinicaltrials.gov; Unique identifier: NCT01813435. Graphical abstract: Changes in central physiological and anatomical parameters according to FFR and QFR match/mismatch quadrants

Ischemia-Related Lesion Characteristics in Patients With Stable or Unstable Angina

Background Postmortem-derived findings support the common beliefs that lipid-rich coronary plaques with a thin, fibrous cap are prone to rupture and that rupture and superimposed thrombosis are the primary mechanisms causing acute coronary syndromes. In vivo imaging with intracoronary techniques may disclose differences in the characterization of atherosclerotic plaques in patients with stable or unstable angina and thus may provide clues to which plaques may rupture and whether rupture and thrombosis are active. Methods and Results We assessed the characteristics of the ischemia-related lesions with coronary angiography and intracoronary angioscopy and determined their compositions with intracoronary ultrasound in 44 patients with unstable and 23 patients with stable angina. The angiographic images were classified as noncomplex (smooth borders) or complex (irregular borders, multiple lesions, thrombus). Angioscopic images were classified as either stable (smooth surface) or thrombotic (red thrombus). The ultrasound characteristics of the lesion were classified as poorly echo-reflective, highly echo-reflective with shadowing, or highly echo-reflective without shadowing. There was a poor correlation between clinical status and angiographic findings. An angiographic complex lesion (n=33) was concordant with unstable angina in 55% (24 of 44); a noncomplex lesion (n=34) was concordant with stable angina in 61% (14 of 23). There was a good correlation between clinical status and angioscopic findings. An angioscopic thrombotic lesion (n=34) was concordant with unstable angina in 68% (30 of 44); a stable lesion (n=33) was concordant with stable angina in 83% (19 of 23). The ultrasound-obtained composition of the plaque was similar in patients with unstable and stable angina. Conclusions Angiography discriminates poorly between lesions in stable and unstable angina. Angioscopy demonstrated that plaque rupture and thrombosis were present in 17% of stable angina and 68% of unstable angina patients. Currently available ultrasound technology does not discriminate stable from unstable plaques